the new colored versions of the mini infidel are using S30V now.Skip the Infidel it's a cool name but that about it, D2 in a OTF I am not a fan of as it can surface rust easily and with an OTF good luck fixing that.
Go with Microtech an Ultratech will be at least $100 cheaper than an Infidel and if you want to spend more I suggest a Scarab or Combat Troodon. Keep it a single edge, as daggers are fragile and difficult at best to sharpen well. The new Microtech M390 blade steel they are using now from Böhler is awesome too.
They have Blue, Green, and FDE. I just special ordered a Green one for someone.